1. Field of the Invention
The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that forms an image on a surface of a recording medium such as print paper using a wet-type electrophotographic technique.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 2006-085063 discloses an invention directed to a fixing device which heats a toner image and fixes the toner image on a recording medium. This fixing device includes an infrared ray transmitting member (conveyance belt). The infrared ray transmitting member is disposed on a printed surface side of a recording medium downstream of the fixing device and transmits infrared rays. This publication describes that unevenness of toner surfaces can be reduced by bringing the infrared ray transmitting member into pressure contact with fused toner.
Japanese Laid-Open Patent Publication No. 2005-284048 discloses an invention directed to a fixing device which imparts gloss to a toner image on a recording medium. This fixing device includes image smoothening means for smoothing a surface of a toner image transferred to a recording medium, and image penetrating means configured as a final stage unit of the fixing device for penetrating the toner image having been subjected to the image smoothening means, into the recording medium without coming into contact with the toner image on the recording medium. According to this publication, in the image forming apparatus including the fixing device, a cross-sectional shape of a surface of an image on the recording medium after subjecting to the fixing follows a cross-sectional shape of a surface of the recording medium that image gloss is changed according to gloss of a recording medium, and images having high gloss can be obtained easily.
Japanese Laid-Open Patent Publication No. 2009-008709 discloses an invention directed to an image forming apparatus which forms an image on a variety of recording media with different glossiness levels. The image forming apparatus includes fixing means for fixing a toner image on a recording medium by applying heat to the toner image, and re-heating means for re-heating the toner image, fixed on the recording medium by the fixing means, to set a glossiness level of the toner image lower than a glossiness level before re-heating. According to this publication, when toner images are to be formed on a variety of recording media with different glossiness levels, evenness of glossiness can be improved stably with optimum glossiness levels without reducing graininess.
If the difference between the glossiness (smoothness) of a recording medium itself and the glossiness of an image fixed on the recording medium is large, the quality as a recording medium is reduced to make the user of the recording medium feel a feeling of strangeness for the recording medium. It is desired that the difference between the glossiness of a recording medium itself and the glossiness of an image fixed on the recording medium should fall within a permissible range.